# Mirdametinib

Source: https://onco.cc/drugs/mirdametinib/  
OnCo record `mirdametinib` (Treatment). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Mirdametinib (Gomekli in the US, Ezmekly in Europe) is a MEK-blocking capsule or dispersible tablet for adults and children with neurofibromatosis type 1 whose plexiform neurofibromas cannot be removed surgically; it is the first such drug approved for adults.

## Summary

Mirdametinib was approved by the FDA in February 2025 for adults and children aged 2 and over with NF1 and symptomatic plexiform neurofibromas not amenable to complete resection, on the ReNeu phase 2b trial in which 41% of adults and 52% of children had a confirmed objective response by central review, with deep and durable responses and improvement in pain. The European Commission granted a conditional marketing authorisation for Ezmekly in July 2025 for the same population. It is the first MEK inhibitor approved for adults with this benign but disabling tumour (selumetinib covered children first). Rash, diarrhoea, nausea, musculoskeletal pain, reduced ejection fraction and ocular toxicity are class effects. Developed by SpringWorks Therapeutics, acquired by Merck KGaA in 2025.

## Fields

- Kind: Treatment
- Status: approved
- Last checked: 2026-09-10
- Also known as: PD0325901; PD 0325901; PD-0325901
- Tags: ema-list
- Brand: Gomekli / Ezmekly
- Modality: Small-molecule allosteric MEK1/2 inhibitor
- Mechanism: Non-ATP-competitive MEK1/2 inhibitor that penetrates the CNS; lowers ERK signalling in NF1-deficient Schwann-lineage cells driving plexiform neurofibromas.
- Approvals: US 2025: NF1 with symptomatic plexiform neurofibromas not amenable to complete resection, adults and children 2 and over (Gomekli); EU 2025: Symptomatic, inoperable plexiform neurofibromas in NF1, age 2 and over (Ezmekly, conditional)

## Notes

- NF1 plexiform neurofibroma is a benign tumour with no cancer record; not linked to a cancer id.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Mirdametinib
- EPAR (EMA): https://www.ema.europa.eu/en/medicines/human/EPAR/ezmekly
- US label (DailyMed): https://dailymed.nlm.nih.gov/dailymed/search.cfm?labeltype=all&query=mirdametinib

## Connected records

- drugs: [Selumetinib](https://onco.cc/drugs/selumetinib/)
- technologies: [Small-molecule kinase inhibitors](https://onco.cc/technologies/kinase-inhibitors/)
- targets: [MEK1/2](https://onco.cc/targets/mek/), [NF1 (neurofibromin)](https://onco.cc/targets/nf1/)
- companies: [Merck KGaA (EMD Serono)](https://onco.cc/companies/merck-kgaa/), [SpringWorks Therapeutics (Merck KGaA)](https://onco.cc/companies/springworks/)
- pathways: [Glioma (KEGG map)](https://onco.cc/pathways/glioma-signalling/), [RAS / RAF / MEK / ERK (MAPK)](https://onco.cc/pathways/ras-mapk/)
- trials: [Mirdametinib in Histiocytic Disorders](https://onco.cc/trials/nct06153173/), [Mirdametinib in Patients With Advanced NF1-mutant Melanoma](https://onco.cc/trials/nct07237100/), [Testing the Effectiveness of the Anti-cancer Drug, Mirdametinib, in Treating Relapsed, Refractory Chronic Lymphocytic Leukemia](https://onco.cc/trials/nct07061951/)
- cancers: [Malignant peripheral nerve sheath tumour (MPNST)](https://onco.cc/cancers/malignant-peripheral-nerve-sheath-tumour/)

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